1. Field of the Invention
The present invention relates to a direct current (DC) link capacitor module, and more particularly, to a DC link capacitor module that may achieve a miniaturization and facilitate a fabrication by connecting a plurality of DC link capacitors using a printed circuit board (PCB).
2. Description of the Related Art
An electric power transmission device of an electric vehicle or a hybrid vehicle, for example, a vehicle using an electrical driving source, includes a battery, a direct current (DC) link capacitor module, an inverter, and a motor.
The battery is used as a power source and the motor is used as a driving source. The inverter receives a pulse width modulation (PWM) duty signal output from a micro process unit (MCU) in order to control a driving velocity and a torque of the motor. The inverter is switched based on the received PWM duty signal, converts DC power output from the battery to alternating current (AC) power, applies the converted power to the motor, and thereby drives the vehicle. The DC link capacitor module smoothens and stabilizes the DC power supplied to the inverter, decreases current ripple, and thereby enables the DC power to be stably supplied to the inverter.
Korean Registration Patent No. 925952 (Patent Document 1), registered on Nov. 2, 2009, discloses a film capacitor module of an inverter having an enhanced cooling performance. Here, a film capacitor module is used for a DC link capacitor module. The film capacitor module configures a single film capacitor cell module by using, as a single group, the respective two film capacitor unit cells disposed in an upper portion and a lower portion. In this instance, the film capacitor module configures a single film capacitor cell module by connecting and thereby installing anode and cathode bus bars at both ends of up and down two film capacitor unit cells, and configures a required capacity of the film capacitor module by combining the configured film capacitor cell module into a plurality of units.
As disclosed in Patent Document 1, in the case of configuring the film capacitor module by connecting a film capacitor that is a DC link capacitor module using a bus bar, the DC link capacitor module may not be miniaturized and a fabrication may become complex. Further, high frequency ripple current may occur due to an increase in equivalent serial resistance (ESR) by the bus bar. Due to the high frequency ripple current, reliability of the DC link capacitor module may be degraded.